#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
#define all(x) begin(x),end(x)
#define rep(i,a,b) for(int i=a;i<b;++i)
#define sz(x) int(x.size())
int main() {
    cin.tie(NULL);
    cin.sync_with_stdio(false);
    int t; cin >> t;
    while(t--) {
        int n; cin >> n;
        vi a(n),b(n);
        for(auto& i : a) cin >> i;
        for(auto& i : b) cin >> i;
        sort(all(a));
        sort(all(b));
        int ans= 0;
        for(int i=0;i<=n;++i) {
            int cur = 1e9+2;
            for(int j=0;j<i;++j) {
                cur=min(cur,abs(a[j+n-i]-b[j]));
                
            }
            for(int j=0;j<n-i;++j) {
                cur=min(cur,abs(b[j+i]-a[j]));
            }
            ans=max(ans,cur);
        }
        cout << ans << '\n';


        

        
        
    }
}